涵蓋平面所有方位角之可切換波束單一導體洩漏波天線陣列

Abstract

本論文設計一輻射波束能涵蓋平面所有方位角之智慧型天線，應用單一導體帶狀洩漏波天線作為天線陣列之單位元素。經由頻譜分析法分析此單一導體帶狀洩漏波天線之傳播常數可知，在一寬頻範圍內，其相位常數會很接近自由空間中的波數，故此天線輻射場型的主波束會固定在端射方向。 由於此單一導體帶狀洩漏波天線之半功率波束寬約為 ，本論文運用十二個單位元素天線來設計能涵蓋平面所有方位角之天線陣列，根據頻譜分析法分析的結果可知，縮短單一導體帶狀洩漏波天線的帶線寬度，能夠增加此天線的半功率波束寬，因此利用此方法即可讓天線陣列之主波束，有效地涵蓋平面所有方位角。之後再將本論文設計之單刀十二擲射頻開關裝置於與此天線陣列，應用射頻開關得以有效地切換於十二個單位元素天線之主波束。最後根據天線量測結果顯示，我們實現了此涵蓋平面所有方位角之可切換波束單一導體洩漏波天線陣列。

In this thesis, we design a switched-beam antenna array covering the whole azimuthal plane, using the single-conductor leaky-wave antennas as the antenna elements. The propagation characteristics of the single-conductor strip leaky-wave antenna are investigated by the spectral domain approach (SDA). Since the phase constant is close to the free-space wavenumber over a very wide bandwidth, the single-conductor strip leaky-wave antenna has a fixed main beam in the endfire direction. Since the half-power beamwidth (HPBW) of the single-conductor strip leaky-wave antenna is around , we use twelve elements to design the antenna array to cover the whole azimuthal plane. From the results of the SDA analysis, we learn that the HPBW of the single-conductor strip leaky-wave antenna is increased if we reduce the width of the strip. Using this method, we can obtain the desired HPBW of the antenna element for the array. Then, we combine a single-pole twelve-throw RF switch with the antenna array to switch the radiation main beam. Finally, the complete antenna array is implemented and its radiation characteristics are measured to verify its validity.